This is an application to continue and expand a Diagnostic Laboratories Core resource for the study of nonhuman primates along with investigative projects directed toward benign prostatic hyperplasia, glomerulonephritis, reproductive failure, diabetes mellitus, and the occurrence of age-related diseases in a large nonhuman breeding facility. The diagnostic laboratories consist of anatomic pathology laboratories, clinical pathologic laboratories, and a clinical reproduction laboratory. This Core provides the staff competence and laboratory resources necessary for the proper medical management of a large nonhuman primate facility, for the recognition of disease processes of biomedical interest and in support of investigational projects. The investigational projects are intended to define the potential usefulness of nonhuman primates for research on benign prostatic hyperplasia, to advance understanding of glomerulonephritis of squirrel monkeys - the primary cause of morbidity and mortality in these animals, to investigate factors affecting reproductive performance in a breeding intensive primate facility, to develop and characterize a colony of diabetic Macaca fascicularis and, finally, to conduct planned searches for monkeys with dyslipoproteinemia, diabetes mellitus, benign prostatic hyperplasia, or the postmenopausal state at the Yemassee Primate Center.